Clutch



O. L. BERBY April 20, 1943.

CLUTCH Filed March 28, 1940 2 Sheets-Sheet 1 DLH April 20, 1943. o, BERBY 2,317,171

CLUTCH Filed March 28, 1940 z sheets-sheet 2 Patented Apr. zo, 1943 CLUTCH Ola L. Berby, Duluth, Minn., assignorto Clyde Iron Works, Duluth, Minn., a corporation of Maine Application March 28, 1930, Serial No. 326,403

3 Claims.

It is the object of the present invention to provide a clutch which includes a clutch drum and a relatively rotatable support. An expandable member is carried by the support designed to engage against the brake drum. A pair of cam races are secured to the ends of the-ex- -pandable member and a cam roller device is provided for engaging the cam races to actuate the same. The last one of the came races is provided with two sections of varying angulari-v ties, one of which when engaged tends to expand the expandable member quickly while the other of which when engaged tends to expand the expandable member more slowly. The two sections of the cam are so arranged that the expandable member will be quickly expanded during the first part of the expansive movement and will be more slowly expanded when the slack in the expandable member has been taken up.

It is a feature of the present invention that the-clutch band is quickly tightened against its drum with a relatively short stroke of the operating control, and at the same time as power is supplied the leverage changes to provide a mechanical advantage in favor of the operator. In other words even the clutch band has been drawn into contact with its drum with a relatively short movementl of the operating control. A relatively longer movement of .the control is required to tighten the band upon its drum. This permits the slack of the band'to be quickly and easily taken up without losing the leverage necessary for the tightening of the bands.

A further feature of the present invention lies inthe particular arrangement of the cam rollers and the manner in which they engage their respective cam races. Two rollers of relatively large diameter engage one cam race, while a relatively smaller diameter cam roller engages the other cam race. As a result the strain is centralized between the cam races and excessive friction is avoided.

Another object of the present invention lies in the particular arrangement of the hydrauli- In the drawings forming a part of my specification z,

Figure 1 is a cross-sectional view through va hoistI showing a hoist drum and disclosing the drum supporting elements.

lFigure 2 is an elevational view of the clutch which secures the drum for rotation with the drum shafts.

Figure 3 is a view of a detail portion of the clutch.

Figure 4 is a detailview of the cam races.

The hoist is provided with a series of parallel vertically extending frame panels III, II, I2, and I3. The panel I0 forms one side of the housing. The panel II provides a supporting panel lining one side of the hoisting drum well I5. The panel I2 forms the opposite wall of the hoisting drum well I5. All of the variouspanels I0, II, I2, I3, and Il are supported upon a base including longitudinally extending beams I1. Y As best illustrated in Figure 1 of the drawings, the drive shaft 30 is supported by asealed ball bearing 3| mounted on the panel II and secured thereto by any suitable means, as by the bolts 32. The shaft 30 extends through the panels II and I2, and is supported by a sealed ball bearing 35 mounted on the panel I3 and secured thereto by bolts 34 and cap 33.

A fan 36 may, if desired, be mounted upon the shaft 30 to cause a circulation of air to ccol the brake and clutch drums which will be later described. A pinion 31 is also positioned on the shaft 30 and rotates therewith when this vshaft 30 is driven by the sprocket 29 from any suitable source of power supply. The pinion is mounted between the sprocketl 29 and the panel II.

A drum shaft 39 extends parallel to the drive shaft 30. A gear 4I is mounted on the shaft 39 to engage the pinion 31 on the drive shaft 30 so that the shaft 39 will rotate when the drive shaft 30 is rotated.

As noted in Figure 1 of the drawings the shaft 39 is supported by a ball bearing 43 secured to the panel Il and by a ball bearing 44 secured to the panel I3 by means of an end cap or plate 45. The cable drum 46 is provided with a cylindrical shell having inwardly extending end flanges 49 and 53. Ball bearings 5I are interposed between these end flanges 49 and 50 and the shaft 39. Circular end cable guide flanges 52 and 53 extend outwardly from the shell l1. The flange 52 extends closely adjacent the panel I2, while the flange 53 is closely adjacent; the panel II. Protecting rings 33 on the panels II and I2 encircle the guide flanges l2 and 53.

I engageable with the clutch drum 58 to cause rotation of the drum 48 with the shaft. A brake y drum 51 is connected to the clutch drum by means of spaced/fins 59, and a brake band encircles the drum 51 in a manner which will be later described.

It will be seen that the drive shaft 88 and the drum shaft 39 are supported by the vertical panels mounted in spaced relationship. Inverted trough-shaped covers 88 and 8| close the top of the space between the panels I8 and and between the panels |2 and |8,respectively. The upper edges of the panels i8, Il, |2, and I8 incline forwardly along substantially the same plane, and thecovers 88 and 8| enclose the gears, and the clutches and brakes, respectively. The hoisting drum well I8 is not covered, the space between the panels and I2 being open to provide access to the hoisting drums or cable drums 48. a

The clutch B is best illustrated in Figures 2, 3, and-4 of the drawings. In this clutch, a collar 85 is mounted on the shaft 89 to rotate with the shaft. A spider 88 extends outwardly from the collar 85, and a pair of spaced arms 81 are formed on this spider 88. Substantially U- shaped clips 89 are secured to the arms 81. These clips 89 straddle the arcuated clutch shoes 98 and 9| which are bolted together at their abutting ends by bolts 92 which extend through end flanges 93. The clips 89 hold the shoes 98 from axial movement. Adjusting bolts 94 extending through the arms 81 adjust the position of the shoes 98 with respect to the arms 81.

The end of the shoe 9| not attached to the shoe 98 is pivotally secured to a pair of links 95 on either side of the spider 86. A pair of lugs 98 are secured to, and extend beyond the end of the shoe 9|. A pivot pin extends through the opposed links 95, the lugs 98, and through an eyebolt 91. The links 85 are pivotally attached to the spider 88 by means of a pivot pin v99. The eye-bolt 91 extends through a shoulder 88 on the spider 88. Nuts |8| on the eye-bolt provide a means of regulating the position of this fastened, or dead, end of the clutch shoes. i

A hydraulic cylinder |82 is pivoted at |83 to the spider 88. A connecting pipe or tube |84 extends from the cylinder |82 to a radial passage |85 through the collar 85 and the shaft 89 to communicate with an axial opening ||8 in the shaft 39. The end |88 of the cylinder |82 is movable ywith respect to the pivot I 83, and supports a transverse pivot |81 upon which is mounted three rollers as illustrated in Figure 3 of the drawings. The outer of these rollers |89 engage against a bearing track ||8 on the spider 88. The center roller Il engages against an inclined track secured to the outer end of the clutch shoe 98. A spring 95' adjustable in tension, extends between the inclined track endof the shoe 98 and the link 95 on each side of the spider 85.

A spring ||2 extends between a bracket ||3 on vthe pivoted end of the cylinder |82 and the extendable or piston end |88 thereof, being connected to a bracket H8'` encircling the relatively movable end of the cylinder |82. This spring tends to hold the rollers |89 and and hydraulic cylinder and piston in retracted position. When fluid is forced into the cylinder |82, however,l the end |88 thereof moves longitudinally. The rollers |89 engage the track |I8, while the roller engages against the considerably angled portion||4 -ot the cam ||5 on the end of 1 of the considerably angled portion ||4 of the cam |l5, and on to the slightly angled portion i8 of the cam |I5. AIt will be seen that longitudinal movement of the roller against the portieril ||8 of the cam ||5 will spread the cam andtrack ||8 apart very slowly. Thus a great- -er leverage is provided to force the clutch shoes l against the drum'after the clutchshoes have been moved into engagement with the drum.

In other words, for a given expansion of the cylinder |82, the friction band will be expanded quickly as long as the roller is in engagement with the portion I|4 of the cam H5.' Theclu-tch band will be quickly expanded into engagement with the clutch drum 58.V At this time, however, the roller is moved into engagement with the portion ||8 of the cam 5. Then for the same given expansion of the cylinder |82, the

friction band will be expanded relatively slowly. Greater leverage is thus acquired when it is needed; andthe amount of pressure required to engage the clutch is reduced.

As has been previously stated, the clutch units and the hoisting drums are identical. Both of the shafts,39 and 48 have central passages or axial openings ||8. As will be later described, hydraulic pressure is introduced into the axial openings by hydraulic cylinders operated by manual control levers.

In accordance with the patent statutes, I have describedl the principles of construction and operation of my hoist; and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that this is oniy'illustrative of a means of carrying out my invention, and that obvious changes may be madeV tively smaller diameter cam roller coaxial with,A

and between, said pair of cam rollers and engageable with said relatively narrow cam race, and

means for urging said cam rollers along said cam surfaces to expand said expandable member.

2. A clutch including a-clutch drum, a support rotatable with respect to said drum, an expandable member supported by said support, a pair of diverging cam races secured to the ends of the expandable member which, whenv actuated,

expand said expandable member, one of said caml races being relatively wide and the other being relatively narrow, a pair of axially spaced coaxial cam rollers engageable with said relatively'wide cam race, a relatively smaller diameter cam roller. coaxial with, and between, said pair of cam rollers, said last named cam roller engaging said relatively narrw cam race. and means for urging said cam rollers between said diverging cam races to expand said expandable member.

3. A clutch including a clutch drum. a support rotatable relative to said drum, an arcuated expandable member supported by said support and expandable against said drum, link means connecting one end of said expandable member to said support. diverging cam races on the ends of said expandable member which. when actuated. expand said expandable member. a pair of spaced coaxial cam rollers engaging the cam race at, one end o! said expandable member. and a cam roller between said spaced cam rollers and coaxiai therewith engaging the other of said cam races.

OLA L. BERBY. 

